All vulnerabilities
CVE-2026-109300GHSA-9wj4-mcm3-ppj6

open-webui: Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds

open-webui open-webui
Open in ThreatlineRecord JSON
CVSS
5.1Medium
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 13 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.18%Chance of exploitation activity in the next 30 days, higher than 7% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in0.11.4Fixed versionCVE List
Published12 Oct 2026Updated 13 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled.

Text from CVE List

Affected versions 2

  • open-webuiaffected: 0.6.31 before 0.11.4CVE List
  • open-webuiunaffected: 0.11.4CVE List

References 2